The Division of lntramural Population Health Research (DIPHR) at the Eunice Kennedy Shriver National Institute of Child Health & Human Development designs and conducts original epidemiological, behavioral, and biostatistical research encompassing several research domains such as human reproduction and development, pregnancy and related complications, pediatric and adolescent health and behaviors, and methodologic research relevant for our mission. The Division comprises three intramural research branches, Epidemiology, Biostatistics & Bioinformatics, and Health Behavior, and its mission is to design and implement original research with the potential for high impact findings for public health and its special populations. Accumulating evidence suggests that adverse intrauterine exposures may lead to permanent fetal adaptations that result in risk of disease later in life. Maternal obesity and gestational diabetes mellitus (GDM) are exposures of particular interest. Thus, the goal of the proposed task order is to follow-up the offspring of an existing cohort of mothers to evaluate impacts of GDM and obesity on the metabolic, vascular, and reproductive health of the offspring, their determinants and the underlying molecular mechanisms. Data from mothers and fathers of the offspring will also be collected to better understand biological mechanisms and pathways. A hybrid design will combine new data collected in the present study with historical data that have been collected. Existing data for cohort mothers (ages 35-60) during the historical follow-up should at least include information on the diagnosis of GDM during the index pregnancy, information on other pregnancy complications, and of type 2 diabetes and related co-morbidities (including, but not limited to cardiovascular disorders), time of their diagnosis, other medical history, reproductive history, pregnancy history, diet and lifestyle factors before and/or during the index pregnancy, and after pregnancy, and anthropometric characteristics in the years after the index pregnancy. Existing data for the offspring (ages 13-35) during the historical follow-up should also include major developmental or chronic disorders (such as asthma and allergies), diet and lifestyle factors, and anthropometric characteristics. The overall study objectives are to recruit and enroll from each of the following 4 exposure categories: a) approximately 1510 offspring with a documented history of in utero GDM exposure, b) approximately 705 offspring of mothers who were overweight (BMl2_:25-29.9 kg/m2) during their pregnancy, c) approximately 705 offspring of mothers who were obese (BMl2_:30 kg/m2) during their pregnancy, and d) approximately 1780 unexposed offspring of mothers who were normal weight and did not have GDM during their pregnancy, as well as approximately 200 sibling groups discordant for GDM.